In recent years, research into nanotechnology has been increasing. Of particular interest is the research into nanomagnetic materials, which may be used for such things as magnetic storage media, nonvolatile memory cells, ferrofluid technology, magnetocaloric refrigeration, biotechnology, and lighting systems, to name a few.
The formation of regular arrays of uniformly distributed ferromagnetic nanoparticles in a matrix material may provide opportunities for reducing the size of magnetic storage media while significantly increasing the storage capacity of such devices. For example, magnetic storage media having bit densities exceeding 10 Tbit/in2 could theoretically be formed from a nanostructure having regular arrays of uniformly distributed magnetic nanoparticles in a matrix material.
Many methods have been developed to fabricate nonostructures having arrays of nanoparticles. For instance, electron-beam lithography methods in the range of 100 nm and above have been developed to create arrays of magnetic nanoparticles. Chemical routes have also been explored wherein a layer-by-layer self-assembly of magnetic nanoparticles are formed. In the chemical self-assembly methods, however, only one or two monolayers may be produced, resulting in nanostructures having two-layers of nanoparticle arrays. Furthermore, many of the currently available methods are expensive and involve multi-step processes including the repetitive formation of resists, energy beam exposure, etching, lift-off, and/or encapsulation.
It is therefore desirable to develop methods for constructing nanostructures with less than 100 nm size and having multiple arrays of uniformly distributed nanoparticles, where size and number density can be controlled precisely. It is particularly desirable to develop methods for forming structures having more than two layers of nanoparticle arrays. Further, methods involving fewer steps than those presently available are desired.